Verified Answer :

World War 1 because as Taskmasters said on this website, "Dadaism was an art movement of the European avant-garde, in the early 20th century, which was heavily influenced by World War I. It was anti-war and anti-bourgeois, and had political affinities with radical left. Some of the key figures of the Dada movement were: Hugo Ball, Emmy Hennings, Hans Arp, George Grosz, Max Ernst, Beatrice Wood, Tristan Tzara, Francis Picabia, etc. The movement influenced later styles in art such as Surrealism, Nouveau Realisme, pop art and Fluxus."   (I quoted another guy's answer a.k.a. Taskmasters.

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